1. Field of the Invention
The present invention relates to a lubricating oil discharge system having a discharge port which is made to open into a bearing bore for a camshaft of an internal combustion engine.
2. Prior Art
In order to supply lubricating oil to a location needing it without any delay immediately an engine is started, it is effective to make a lubricating oil passage as short as possible, but if trying to connect an oil pump provided in the vicinity of a crankshaft to a camshaft bearing provided in a cylinder head at the shortest distance, a lubricating oil discharge port has to be opened in a lower side of the camshaft bearing.
However, if a lubricating oil discharge port is made to open in a lower side of a camshaft bearing, all lubricating oil in a bearing bore eventually drops into an oil pan when the engine is stopped, and it becomes highly probable that film lubrication is no longer effective when the engine is restarted.